Back in 1978, I was admitted to Northwestern Polytechnical University.

Chapter 515 Dissatisfied with the progress being behind schedule? Call your fourth uncle over!
Back then, our equipment was outdated, but we had the spirit to fight to the death!
However, with the development of technology, it has become increasingly difficult for the backward side to win. No matter how brave they are, the only effect they can have is to waste another missile of the enemy.

If you fall behind, you will be beaten!

Fortunately, ours is the most advanced right now!

Hearing Lei Qiang's words, everyone was filled with emotion. Old Lin looked at the empty racks under the wings with a complicated expression.

"Last year, we equipped ourselves with two hundred fighter jets, and this year's order is for three hundred more. With these five hundred aircraft, our air force will be much more relaxed."

In recent years, Factory 132 has outsourced its foreign trade orders to its sister factories and focused all its efforts on producing orders for the Air Force. Moreover, the speed of its production is astonishing.

This is a third-generation fighter jet!
"Yes, with the merger of Factory 132 and Institute 611, Northwestern Polytechnical University also held a certain stake and invested heavily in building new production lines, which allowed the production capacity to be released." Another Air Force leader chimed in, "If it weren't for the new production lines, the progress wouldn't have been so fast!"

Qin Liang was a little embarrassed: "We at Northwestern Polytechnical University actually don't want to get involved..."

"No, no, you're right to interfere!"

"Principal Qin, Principal Qin!"

Just then, someone ran over.

"what happened?"

"At the school, the Russians want to see you; they're standing outside the principal's office and won't leave!"

Qin Liang frowned: "What is it?"

"It's probably because their MiG-1.42 project is progressing slowly, and the Russians are getting impatient."

We initially approached Northwestern Polytechnical University (NPU) for collaboration because we were impressed by its research and development capabilities. However, we never expected that while Europe's Typhoon fighter jet had already undergone a facelift, their aircraft was still not designed.

The Russians finally reached their breaking point!

The door to the principal's office.

"Everyone, Principal Qin really has other matters to attend to and is not at school. I will inform you as soon as he returns," Yu Zhi kindly advised, but these Russians simply wouldn't listen!

"Hmph, the Europeans have all gone back to building prototypes, where are our design drawings? Why haven't they come out yet?"

Northwestern Polytechnical University helped them design the exterior, and it was finished in less than a month. Now... a year has passed, and the structural design drawings for the fuselage are still not out!

The Russians are angry, and the consequences will be severe!

Tap tap tap... Footsteps sounded.

"Everyone, the structural design drawings for the mechs have been delayed for so long, and it's all your fault!"

The Russians were taken aback.

Principal Qin is back?

Wait, how is this our fault?

“Principal Qin, what do you mean by this?” Nikolai Nikitin frowned.

"If you don't hand over the engine to us, how are we supposed to match it? Aircraft design is a complex system where a small change can have far-reaching consequences. Even a problem with the air intake can lead to the entire aircraft being scrapped and redesigned. You're all experts, so I don't need to say more, right? Come on in and let's talk."

The Russians were stunned.

After the aerodynamic shape was blown out, Qin Liang made a request, and they agreed at the time, but after returning...

The Lyulka Design Bureau disagreed!
In their eyes, these were clearly Eastern technicians trying to steal the technological achievements of their Lyulka Design Bureau!
For a long time, Dongfang has been associated with a bad reputation for copying, and the Lyulka Design Bureau certainly doesn't want their most advanced engine to be copied by Dongfang!
When the development of the new generation of fighter jets began, the development of the supporting engines had already been underway for some time.

In early 1981, research and development work began, with a thrust requirement of 18 to 20 tons. The Lyulka Design Bureau, the research and development unit of the AL-31F engine, was assigned to the research and development work. The project was secretly codenamed Product 20. After mass production, the installed model was called AL-41F, following the numbering system of the Lyulka Design Bureau.

That's right, this is the famous Fourth Uncle!

In later generations, the Russian Su-57 also used the AL-41F engine, and some even call it the AL-51F engine. On the surface, it sounds like the engine has stronger performance, but in reality, it is not the same as the Soviet-era AL-41F at all.

The AL-41F engine used above, codenamed 117S, is actually a third-generation engine, improved by incorporating some technologies from the fourth-generation Soviet engine. The thrust of a single engine is only 14.5 tons! It is far from the real fourth-generation engine.

As for the AL-51F, although the Russians boasted that a single engine could deliver 19 tons of thrust, the generally accepted data shows that its afterburning thrust is only 17 tons, which is still far from the level of the Soviet-era AL-51F.

It can be said that since the collapse of the Soviet Union, Russia's aircraft engines have not made any progress and have been relying on their past achievements!

My fourth aunt's husband from the Soviet era had truly advanced technology!
Now, we need to use the MiG 1.44 project to get this engine from the Russians. If you don't give it to us, we can't design it!
When the Russians walked into the office, they were no longer as aggressive as they had been initially. They already knew that the project couldn't go on, and it wasn't the fault of the Easterners, but their own!
but……

"I know what the Lyulka Design Bureau is thinking. They think this engine is too advanced and are afraid that Northwestern Polytechnical University will copy the technology?" Qin Liang rolled his eyes at these people: "Hmph, I'm not bragging, but the United States, which has the most advanced aero-engine technology, is looking for us to jointly develop. You know the YF-23, right? The YF-120 engine used on it was jointly developed by General Electric and us."

"Our Soviet engines are more advanced than those of the United States!"

"That's right. If we're comparing individual metrics, like thrust, your engines can rival those of the West. But besides thrust, what other metrics do you have that can match those of the United States?"

Qin Liang sat on his large sofa and looked at the person opposite him: "When it comes to thrust-to-weight ratio, your engine is calculated based on dry weight, while Western engines are calculated based on wet weight. Let's talk about it. The F100's thrust-to-weight ratio can reach 8 under wet weight. Can your AL-31F do that?"

The Russians fell silent.

They also boasted that their engine's thrust-to-weight ratio could reach 8, but there are many tricks involved in this calculation.

Dry weight is the weight of a freshly manufactured engine before lubrication. However, for an aircraft engine to fly, lubrication and other components must be added, which can increase the weight by 5% to 10%.

Of course, the Americans later learned this bad habit, and there was something fishy about the thrust-to-weight ratio of the F119, but it really wasn't true for third-generation fighters.

"As for lifespan, your engines are even less comparable. Even just considering the overhaul cycle, your engines last at most two or three hundred hours, while our engines last over a thousand hours. How can you compare them? What, you're still not convinced? What are you trying to say, World War II experience? How many years has it been since World War II ended? Has war started again?"

Based on the experience of World War II, an aircraft would not last more than 100 hours from the time it leaves the factory until it is destroyed, so a lifespan of 200 to 300 hours is sufficient.

If war were to break out, the Russian plan would definitely be the most suitable. The problem is, this war has never actually started!

In peacetime, however, these designs by the Russians become quite unusable.

The engine needs to be replaced every two to three hundred hours, making the total cost of this aircraft very high over its entire lifespan!
Early MiG-21s and similar aircraft had engine lifespans of only fifty hours; they were either replacing engines or on their way to replace them!

"Your engines have short lifespans not because of any war experience, but because your technology is backward. To achieve the same performance as the West, you have to squeeze out the potential, which leads to a reduction in engine lifespan!" Qin Liang rolled his eyes at the other party: "From precision machining to advanced materials, you are behind the Western world. The only thing you are advanced in is your integration capabilities."

The fact that they could produce engines with the same performance as those from the West using outdated materials and processing techniques truly speaks volumes about their strong integration capabilities.

The Russians had complicated expressions.

"I don't know what the Lyulka Design Bureau was thinking. It was clearly a win-win collaboration, but they insisted on keeping it to themselves. Their vision is too narrow. They have no idea that Northwestern Polytechnical University's technology is the best in the world!"

Qin Liang looked at everyone present and said, "Your projects are lagging behind, which has nothing to do with us. It's all because of Liruka's lack of cooperation. You have two options now."

"Principal Qin, please speak."

"First, we need to get the Lyulka Design Bureau to cooperate with us seriously. We can not only help match the engine to the fighter jet, but we can also provide suggestions to make the engine's performance more advanced! If I'm not mistaken, there are definitely countless technical problems waiting for them with this brand-new engine. Not to mention, they probably can't even make a controller."

We'll design it for you!
My third aunt's husband used hydraulic control before, a huge controller attached to the engine, while the West has long used electronic control, which is solved by a small control box the size of a dictionary!

When it came to the fourth uncle, to achieve the linkage between propulsion and combustion, digital control was required, which gave the Russians a major headache. Besides this, there were other things, such as engine blade design, how to increase the pressure ratio, and for turbines, how to use special ceramic materials, etc., the Russians lacked in all of these areas!
With the help of Northwestern Polytechnical University, this engine will be easier to build, and... we might even be able to use Northwestern Polytechnical University to transform it into a variable cycle engine!

"Secondly, we should completely abandon the Lyulka Design Bureau and use our engine for matching. After all, we know the parameters and can complete the matching as soon as possible. When you need to modify it later, you can do it yourself. Anyway, Lyulka doesn't want to show us their technology, so we might as well just ignore them."

The latter is certainly not suitable, since they cannot purchase engines in large quantities from the East, and they would have to spend a lot of time and effort to modify them themselves later.

Of course, this isn't unheard of. When an aircraft comes out but the engine still has problems, an older engine will be used for test flights.

For example, the Su-27 used the WS-25 turbofan engine during its test flights, and the J-9 fighter jet used the WP-15 turbofan engine during its test flights, but now it is in mass production and uses the WS-10 turbofan engine.

Replacing the engine is possible, as long as you can accept the enormous amount of work required for it!
But now... the Russians are obviously unwilling, after all, they don't have top-notch computer-aided design capabilities!
Nikolai Nikitin took a deep breath: "Alright, I'll go back and check on the Lyulka Design Bureau."

In March 1946, Akim Mikhailovich Lyulka founded the Lyulka Design Bureau in Rybinsk, specifically responsible for the development of jet engines.

In 1947, they developed the Soviet Union's first domestically produced turbojet engine, which was installed on the Su-11 fighter jet.

The AL-21F series turbojet engines, developed in the 1950s, were used in aircraft such as the Su-17 and Su-24.

Of course, what truly made the Lyulka Design Bureau shine was the AL-31F engine developed during the third-generation engine era. It became the core power of the Su-27, and with the export of the Su-27, this engine became the main engine of many countries' air forces.

For example, in the East, for a long time, we have relied on the J-30 to fly. The twin-engine J-11 and the single-engine J-10 both use the J-30!

In 1982, the Lyulka Design Bureau was incorporated into the Saturn Research and Production Corporation, but it still retained its independent rights and was very strong in engine design.

At that moment, at number 179 Lenin Avenue in Rybinsk, Ryazan Oblast, a group of people were still diligently conducting their research.

The best way to increase the power of an aircraft engine is to increase the turbine inlet temperature!

According to conventional analysis, if the turbine inlet temperature is increased by 100 degrees Celsius, the engine thrust can be increased by 20%!
If my fourth aunt's husband wants to achieve a thrust output of 18 tons, then the turbine inlet temperature needs to reach... 1828K!

This temperature is actually lower than that in the West!

Historically, the F119 had a turbine inlet temperature as high as 1977K, while the Rafale engine, due to its poor compressor, could only try to increase the turbine inlet temperature as much as possible. On the M88-2, the turbine inlet temperature reached as high as 1850K!

In comparison, the turbine inlet temperature of the EJ200 engine is only 1803K.

This shows how bad the French technology is; they achieved lower performance parameters than the EJ200 by using a higher turbine inlet temperature!

The temperature Lyulika chose wasn't the highest, but it was still 163K higher than her third aunt's 1665K!

Moreover, with such a significant increase in the temperature reaching the turbine, the temperature inside the combustion chamber must be even higher, increasing by 250K!

"The combustion chamber has cracked again!" An engineer said to Dr. Che Jin, holding up the outer wall of the combustion chamber from the recent experiment. "In our experiment, the internal temperature of the combustion chamber fluctuated by as much as plus or minus 120 degrees Celsius. The inner wall of this combustion chamber couldn't withstand the sudden temperature changes..."

There are many technical challenges to overcome!

Dr. Che Jin, the person in charge of Fourth Aunt's husband, frowned deeply: "Yes, this is a big problem. To solve this problem, we need to utilize the floating wall combustion chamber..."

A floating wall combustion chamber refers to a combustion chamber whose inner wall is made up of multiple independent heat-resistant alloy linings. There are gaps between the linings and the combustion chamber wall, which allows air to pass through and form an air film, thereby controlling the temperature of the combustion chamber wall within a tolerable range.

The high-pressure air drawn from the compressor passes through the liner to form a cooling film, which isolates the high-temperature combustion. At the same time, part of the airflow cools the back of the liner, forming double thermal protection.

In this way, the cooling efficiency can be improved by more than 30%!

The American Fang 119 engine uses this technology to improve cooling performance.

To manufacture this structure, you need advanced CNC machine tools!

“The turbine wear has worsened!” Another engineer walked in, carrying a severely worn turbine.

"We still need to further improve the dynamic balance tolerance of the turbine." Dr. Che Jin's brows furrowed even deeper.

Even a car wheel needs to be dynamically balanced, otherwise it will generate extra vibration when it runs fast. This is even more true for a turbocharger that can easily reach tens of thousands of revolutions per minute!

With the Russians' manufacturing methods, the dynamic balance tolerance of the turbine can be controlled at most 0.8g*mm, while in contrast, advanced Western technology can reach 0.2!

Aero engines: the crown jewel of industry!

If the materials and processing technology are not up to standard, it will be impossible to manufacture advanced aero engines!
The Russians have first-rate integration methods, but their backward foundation still limits their progress!
"If only we had advanced processing equipment!"

"Yes, this kind of equipment is all controlled by the West..."

"Is it only found in the West?"

"Besides the West, there's Northwestern Polytechnical University..."

Upon hearing his subordinate's words, Dr. Che Jin's expression became even more complicated.

That's right, besides the West, there's Northwestern Polytechnical University. Now, with the easing of relations between the Soviet Union and the East, many institutions are flocking to the East seeking cooperation! However…

The Lyulka Design Bureau was arrogant and disdained to cooperate with the East. After all, the East had previously been their little brother, and now it was suddenly riding on their heads, which was hard to accept!

"Dr. Che Jin, Comrade Nikolai from the Mikoyan Design Bureau has arrived!"

Nikolai Nikitin?
Dr. Che Jin nodded: "Okay, I'll go find him later."

Dr. Cha Kim took off his white coat, revealing a suit underneath, looked at himself in the mirror, and then walked out.

Reception room.

"Nikolai, what brings you here?"

"Our MiG-1.44 project needs matching engine data. How is your engine development progressing? Can you provide us with all the data?"

"Well..."

It's not that they don't want to give it, but their work is still in a mess. If they give the data now, and things change later, wouldn't all the work they've done now be wasted?

The difficulty of building this engine is much greater than the difficulty of getting my third aunt's husband back then!
"By the way, Nikolai, you have good relations with the East, could you perhaps..."

"Say!"

"Could we purchase a batch of advanced CNC machine tools from them?"

"I don't know. People from the East are more willing to have you do the manufacturing directly. How about... you send them the part design drawings first and let them help with the manufacturing?"

Nikolai Nikitin also knew that it would be difficult to get Dr. Che Jin to agree to jointly design the engine with the East. It would be better to process a batch of parts for them first to demonstrate the East's excellent technical level. This way, Dr. Che Jin's psychological defenses would gradually weaken!
"it is good!"

a week later.

"This...this precision is incredible! The floating wall combustion chamber, the Easterners have actually built it!"

"Yes, this turbine has undergone advanced processing, and the dynamic balance tolerance has been controlled to 0.2!"

Two key technical challenges were solved by people from the East!
"Gentlemen, Eastern technology is so advanced that it has long exceeded our expectations. Cooperating with the East is the best course of action." Nikolai Nikitin pressed on while the iron was hot: "If we cooperate with the East, the Product-20 can definitely be developed as soon as possible, and it can even be modified into a variable cycle engine!"

(End of this chapter)